Person.prototype.lastName = '曹'


function Person(name) {
    this.name = name
}

var person = new Person('善诚')

// person.lastName = '陈'
// console.log(person.lastName);//陈
// console.log(person.prototype.lastName);//曹

//改
// Person.prototype.lastName = 陈
// console.log(person.lastName);

// 删
delete person.lastName //不行




function Bus() {

}

Car.prototype = {
    constructor: Bus
}

function Car() {

}

var car = new Car ()
console.log(car.constructor);// function: Bus
//constructor指向Car(),为了让Car这个函数构造出来的所有的对象想要找到它的构造器的时候